Note that this document supersedes the previous version. Updates will be posted as new information becomes available.

1. What is the influenza A(H7N9) virus?

Influenza A H7 viruses are a group of influenza viruses that normally circulate among birds. The influenza A(H7N9) virus is one subgroup among the larger group of H7 viruses. Although some H7 viruses (H7N2, H7N3 and H7N7) have occasionally been found to infect humans, no human infections with H7N9 viruses have been reported until recent reports from China.

2. What are the main symptoms of human infection with influenza A(H7N9) virus?

Thus far, patients with this infection have had severe pneumonia. Symptoms include fever, cough and shortness of breath. However, information is still limited about the full spectrum of disease that infection with influenza A(H7N9) virus might cause.

3. How many human cases of influenza A(H7N9) virus have been reported in China to date?

As of 3 April 2013, seven laboratory-confirmed cases have been detected in China. Details of the most current information on cases can be found in Disease Outbreak News.

4. Why is this virus infecting humans now?

We do not know the answer to this question yet, because we do not know the source of exposure for these human infections. However, analysis of the genes of these viruses suggests that although they have evolved from avian (bird) viruses, they show signs of adaption to growth in mammalian species. These adaptations include an ability to bind to mammalian cells, and to grow at temperatures close to the normal body temperature of mammals (which is lower than that of birds).

5. What is known about previous human infections with H7 influenza viruses globally?

From 1996 to 2012, human infections with H7 influenza viruses (H7N2, H7N3, and H7N7) were reported in Netherlands, Italy, Canada, USA, Mexico and the United Kingdom. Most of these infections occurred in association with poultry outbreaks. The infections mainly resulted in conjunctivitis and mild upper respiratory symptoms, with the exception of one death, which occurred in the Netherlands. Until now, no human infections with H7 influenza viruses have been reported in China.

6. Is the influenza A(H7N9) virus different from influenza A(H1N1) and A(H5N1) viruses?

Yes. All three viruses are influenza A viruses but they are distinct from each other. H7N9 and H5N1 are considered animal influenza viruses that sometimes infect people. H1N1 viruses can be divided into those that normally infect people and those that normally infect animals.

7. How did people become infected with the influenza A(H7N9) virus?

Some of the confirmed cases had contact with animals or with an animal environment but the virus has not thus far been found in animals. It is not yet known how these persons became infected. The possibility of animal-to-human transmission is being investigated, as is the possibility of person-to-person transmission.

8. How can infection with influenza A(H7N9) virus be prevented?

Although both the source of infection and the mode of transmission are uncertain, it is prudent to follow basic hygienic practices to prevent infection. They include hand and respiratory hygiene and food safety measures.

Hand hygiene:? Wash your hands before, during, and after you prepare food; before you eat; after you use the toilet; after handling animals or animal waste; when your hands are dirty; and when providing care when someone in your home is sick. Hand hygiene will also prevent the transmission of infections to yourself (from touching contaminated surfaces) and in hospitals to patients, health care workers and others. ? Wash your hands with soap and running water when visibly dirty; if not visibly dirty, wash your hands with soap and water or use an alcohol-based hand cleanser.

Respiratory hygiene:? Cover your mouth and nose with a medical mask, tissue, or a sleeve or flexed elbow when coughing or sneezing; throw the used tissue into a closed bin immediately after use; perform hand hygiene after contact with respiratory secretions.

9. Is it safe to eat meat, i.e. poultry and pork products?

Although we do not yet know the mode of transmission, it is prudent to follow basic principles of hygienic food preparation, as follows: Diseased animals should not be eaten. Otherwise, it is safe to eat properly prepared and cooked meat. Because influenza viruses are inactivated by sufficient heating, normal temperatures used for cooking (such that food reaches 70°C in all parts— "piping" hot — no "pink" parts) will kill the virus. In areas experiencing outbreaks, meat products can be safely consumed provided that these items are properly cooked and properly handled during food preparation. The consumption of raw meat and uncooked blood-based dishes is a high-risk practice and is discouraged. Always keep raw meat separate from cooked or ready-to-eat foods to avoid contamination. Do not use the same chopping board or the same knife for raw meat and other foods. Do not handle both raw and cooked foods without washing your hands in between and do not place cooked meat back on the same plate or surface it was on before cooking. Do not use raw or soft-boiled eggs in food preparations that will not be heat treated or cooked. After handling raw meat, wash your hands thoroughly with soap and water. Wash and disinfect all surfaces and utensils that have been in contact with raw meat.

10. Is there a vaccine for the influenza A(H7N9) virus?

No vaccine for the prevention of influenza A(H7N9) infections is currently available. However, viruses have already been isolated and characterized from the initial cases. The first step in development of a vaccine is the selection of candidate viruses that could go into a vaccine. WHO, in collaboration with partners, will continue to characterize available influenza A(H7N9) viruses to identify the best candidate viruses. These candidate vaccine viruses can then be used for the manufacture of vaccine if this step becomes necessary.

11. Does treatment exist for influenza A(H7N9) infection?

Laboratory testing conducted in China has shown that the influenza A(H7N9) viruses are sensitive to the anti-influenza drugs known as neuraminidase inhibitors (oseltamivir and zanamivir). When these drugs are given early in the course of illness, they have been found to be effective against seasonal influenza virus and influenza A(H5N1) virus infection. However, at this time, there is no experience with the use of these drugs for the treatment of H7N9 infection.

12. Is the general population at risk from the influenza A(H7N9) virus?

We do not yet know enough about these infections to determine whether there is a significant risk of community spread. This possibility is the subject of epidemiological investigations that are now taking place.

13. Are health care workers at risk from the influenza A(H7N9) influenza virus?

Health care workers often come into contact with patients with infectious diseases. Therefore, WHO recommends that appropriate infection prevention and control measures be consistently applied in health care settings, and that the health status of health care workers be closely monitored. Together with standard precautions, health care workers caring for those suspected or confirmed to have influenza A(H7N9) infection should use additional precautions (http://www.who.int/csr/resources/publications/swineflu/WHO_CDS_EPR_2007_6/en/index.html).

14. What investigations have begun?

Local and national health authorities are taking the following measures, among others: ? Enhanced surveillance for pneumonia cases of unknown origin to ensure early detection and laboratory confirmation of new cases; ? Epidemiological investigation, including assessment of suspected cases and contacts of known cases;? Close collaboration with animal health authorities to determine the source of the infection.

15. Does this influenza virus pose a pandemic threat?

Any animal influenza virus that develops the ability to infect people is a theoretical risk to cause a pandemic. However, whether the influenza A(H7N9) virus could actually cause a pandemic is unknown. Other animal influenza viruses that have been found to occasionally infect people have not gone on to cause a pandemic.

16. Is it safe to travel to China?

The number of cases identified in China is very low. WHO does not advise the application of any travel measures with respect to visitors to China nor to persons leaving China.

17. Are Chinese products safe?

There is no evidence to link the current cases with any Chinese products. WHO advises against any restrictions to trade at this time.

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Note that this document supersedes the previous version. Updates will be posted as new information becomes available.注意，本文件已取代之前的版本。一旦有新的信息出现，更新将会发布。1. What is the influenza A(H7N9) virus?1.什么是甲型流感A(H7N9)病毒?Influenza A H7 viruses are a group of influenza viruses that normally circulate among birds. The influenza A(H7N9) virus is one subgroup among the larger group of H7 viruses. Although some H7 viruses (H7N2, H7N3 and H7N7) have occasionally been found to infect humans, no human infections with H7N9 viruses have been reported until recent reports from China.甲型流感A H7型病毒群是一类通常在禽鸟类体内传播的流感病毒的集合。甲流A(H7N9)病毒是H7型病毒群的一个子群。尽管一些H7型病毒(H7N2,H7N3和H7N7)偶尔被发现可感染于人类，直到最近来自中国的报道之前，尚没有人类感染过H7N9病毒的报告。2. What are the main symptoms of human infection with influenza A(H7N9) virus?2.感染甲流A(H7N9)病毒的人有哪些主要症状?Thus far, patients with this infection have had severe pneumonia. Symptoms include fever, cough and shortness of breath. However, information is still limited about the full spectrum of disease that infection with influenza A(H7N9) virus might cause.到目前为止,有这种感染的患者已有严重的肺炎。症状包括发烧、咳嗽和气短。然而,感染甲流A(H7N9)病毒可能引起的疾病谱的全貌，目前的信息仍然是有限的。3. How many human cases of influenza A(H7N9) virus have been reported in China to date?3.在中国，就目前为止，有多少人例甲流A(H7N9)病毒感染已被报道？As of 3 April 2013, seven laboratory-confirmed cases have been detected in China. Details of the most current information on cases can be found in Disease Outbreak News.??截至2013年4月3日,在中国已发现7例实验室确诊病例。目前大多数病例的细节信息可以在“疾病暴发新闻”上查到。4. Why is this virus infecting humans now?4.这种病毒为什么会感染人类?We do not know the answer to this question yet, because we do not know the source of exposure for these human infections. However, analysis of the genes of these viruses suggests that although they have evolved from avian (bird) viruses, they show signs of adaption to growth in mammalian species. These adaptations include an ability to bind to mammalian cells, and to grow at temperatures close to the normal body temperature of mammals (which is lower than that of birds).我们还不知道这个问题的答案,因为我们不知道这些人类感染的接触源。然而,分析这些病毒的基因表明,尽管他们的祖先来自禽(鸟)流感病毒,他们表现出在哺乳动物身上的生长适应性。这些适应性包括绑定于哺乳动物细胞,并生长在接近哺乳动物正常体温的温度 (低于禽鸟类)。5. What is known about previous human infections with H7 influenza viruses globally?5.之前已知的关于全球范围内的甲型流感H7型病毒感染的信息是什么?From 1996 to 2012, human infections with H7 influenza viruses (H7N2, H7N3, and H7N7) were reported in Netherlands, Italy, Canada, USA, Mexico and the United Kingdom. Most of these infections occurred in association with poultry outbreaks. The infections mainly resulted in conjunctivitis and mild upper respiratory symptoms, with the exception of one death, which occurred in the Netherlands. Until now, no human infections with H7 influenza viruses have been reported in China.从1996年到2012年,人类感染甲型流感H7型病毒(H7N2,H7N3,H7N7)的病例先后被报道于荷兰、意大利、加拿大、美国、墨西哥和英国。 这些感染的发生多伴随禽流感的爆发。感染主要导致结膜炎和轻微的上呼吸道症状,除了在荷兰发生了一例死亡。目前为止, 在中国没有人类曾感染过甲型流感H7型病毒的报道。6. Is the influenza A(H7N9) virus different from influenza A(H1N1) and A(H5N1) viruses?6.甲型流感(H7N9)型病毒是不同于甲型流感(H1N1)和(H5N1)型的一种病毒吗?Yes. All three viruses are influenza A viruses but they are distinct from each other. H7N9 and H5N1 are considered animal influenza viruses that sometimes infect people. H1N1 viruses can be divided into those that normally infect people and those that normally infect animals.是的。所有三个病毒是A型流感病毒,但他们彼此不同。H7N9和H5N1病毒被认为是动物流感病毒，偶尔可感染人类。H1N1病毒则可分为通常感染人类的类型与通常感染动物的类型。7. How did people become infected with the influenza A(H7N9) virus?7.人们是怎么感染甲流A(H7N9)病毒的?Some of the confirmed cases had contact with animals or with an animal environment but the virus has not thus far been found in animals. It is not yet known how these persons became infected. The possibility of animal-to-human transmission is being investigated, as is the possibility of person-to-person transmission.一些确诊病例有接触过动物或处于动物环境，但是到目前为止病毒还没有在动物身上被发现。现在还不清楚这些人如何被感染。动物与人之间传播的可能性正在被调查,不排除人际传播的可能性。8. How can infection with influenza A(H7N9) virus be prevented?8.怎样可以避免感染甲流A(H7N9)病毒?Although both the source of infection and the mode of transmission are uncertain, it is prudent to follow basic hygienic practices to prevent infection. They include hand and respiratory hygiene and food safety measures. 尽管感染源和传播方式都是不确定的,但应谨慎地遵循基本的卫生习惯以预防感染。包括手和呼吸道卫生，以及食品安全的相关措施。Hand hygiene:手卫生:? Wash your hands before, during, and after you prepare food; before you eat; after you use the toilet; after handling animals or animal waste; when your hands are dirty; and when providing care when someone in your home is sick. Hand hygiene will also prevent the transmission of infections to yourself (from touching contaminated surfaces) and in hospitals to patients, health care workers and others. ?在准备食物之前、期间和之后;在进食之前；在用完厕所后;在接触动物或动物排泄物后；当你的手很脏；当在照料家中的病人时，这些情况都要注意洗手。手卫生也会防止感染传播到自己(从触摸被污染的表面)和在医院的病人,卫生保健工作者和其他人。? Wash your hands with soap and running water when visibly dirty; if not visibly dirty, wash your hands with soap and water or use an alcohol-based hand cleanser. ?当手看起来很脏，注意用肥皂和流动水洗手;如果不是看起来很脏,可用肥皂和水清洗双手或用含酒精类的洗手液。Respiratory hygiene:呼吸道卫生:? Cover your mouth and nose with a medical mask, tissue, or a sleeve or flexed elbow when coughing or sneezing; throw the used tissue into a closed bin immediately after use; perform hand hygiene after contact with respiratory secretions.? 当咳嗽或喷嚏时，用医学面具、材料，或卷筒，或弯曲肘部以盖住嘴巴和鼻子；把用过的材料立即扔进附近的垃圾箱里; 在接触呼吸道分泌物后执行手卫生。9. Is it safe to eat meat, i.e. poultry and pork products?9.是否可以安全食用肉类,例如家禽和猪肉产品?Although we do not yet know the mode of transmission, it is prudent to follow basic principles of hygienic food preparation, as follows: Diseased animals should not be eaten. Otherwise, it is safe to eat properly prepared and cooked meat. Because influenza viruses are inactivated by sufficient heating, normal temperatures used for cooking (such that food reaches 70°C in all parts— "piping" hot — no "pink" parts) will kill the virus. In areas experiencing outbreaks, meat products can be safely consumed provided that these items are properly cooked and properly handled during food preparation. The consumption of raw meat and uncooked blood-based dishes is a high-risk practice and is discouraged. Always keep raw meat separate from cooked or ready-to-eat foods to avoid contamination. Do not use the same chopping board or the same knife for raw meat and other foods. Do not handle both raw and cooked foods without washing your hands in between and do not place cooked meat back on the same plate or surface it was on before cooking. Do not use raw or soft-boiled eggs in food preparations that will not be heat treated or cooked. After handling raw meat, wash your hands thoroughly with soap and water. Wash and disinfect all surfaces and utensils that have been in contact with raw meat.尽管我们还不知道传播方式,但应谨慎地遵循基本的卫生原则准备食物,如下:患病的动物不应该被吃掉。另外,可以安全食用妥善制备和烹调的肉类。因为足够的加热可灭活流感病毒,烹饪过程的正常温度(如各部分均匀受热至70°C的食品——“管道”热——没有“粉红色”部分)可以杀死病毒。在疫情暴发地区, 提供妥善煮熟,并在食品制备过程中妥善处理，则肉类产品可以被安全食用。食用生肉和未加工的血食菜品是一项高风险的实践,并不提倡。始终保持原料肉和煮熟或直接入口的食物分开,以避免污染。不要使用相同的切菜板或同一把刀对原料肉和其他食物进行处理。不要在没有洗手间同时处理生的和熟的食物,不要将煮熟的肉放回到烹饪前的菜板或器皿表面。不要使用生的或煮得半熟的蛋准备 不加热处理或烹煮的食物。在处理生肉前,彻底用肥皂和水洗手。清洗和消毒所有接触生肉的界面和器具。10. Is there a vaccine for the influenza A(H7N9) virus?10.针对甲流A(H7N9)病毒有疫苗吗？No vaccine for the prevention of influenza A(H7N9) infections is currently available. However, viruses have already been isolated and characterized from the initial cases. The first step in development of a vaccine is the selection of candidate viruses that could go into a vaccine. WHO, in collaboration with partners, will continue to characterize available influenza A(H7N9) viruses to identify the best candidate viruses. These candidate vaccine viruses can then be used for the manufacture of vaccine if this step becomes necessary.预防甲流A(H7N9)病毒感染的疫苗目前尚无可用的。然而, 从最初的病例中，病毒已经被隔离和描述。疫苗发展的第一步是选择可以成为疫苗的候选病毒。WHO与其他协作者,将继续描述可用的甲流A(H7N9)病毒型以识别最佳候选。这些候选疫苗病毒可以被用于制造疫苗，如果这一步成为必要。11. Does treatment exist for influenza A(H7N9) infection?11.是否存在对甲流A(H7N9)病毒感染的治疗途径?Laboratory testing conducted in China has shown that the influenza A(H7N9) viruses are sensitive to the anti-influenza drugs known as neuraminidase inhibitors (oseltamivir and zanamivir). When these drugs are given early in the course of illness, they have been found to be effective against seasonal influenza virus and influenza A(H5N1) virus infection. However, at this time, there is no experience with the use of these drugs for the treatment of H7N9 infection.在中国进行的实验室检测显示,甲流A(H7N9)病毒对病毒抗流感药物，称为神经氨酸酶抑制剂(奥司他韦和扎那米韦) ，是敏感的 。当这些药物被使用于早期的发病过程中,它们被发现对抗季节性流感病毒和甲型H5N1禽流感病毒感染是有效的。然而目前,,使用这些药物治疗H7N9感染是没有相关经验的 。12. Is the general population at risk from the influenza A(H7N9) virus?12.普通人群是否处于甲流A(H7N9)病毒感染的危险当中?We do not yet know enough about these infections to determine whether there is a significant risk of community spread. This possibility is the subject of epidemiological investigations that are now taking place.我们尚未充分了解这些感染，以决定是否存在重大的社区传播风险 。这可能是现在正在进行的流行病学调查的主题。13. Are health care workers at risk from the influenza A(H7N9) influenza virus?13.卫生保健工作者是否面临甲流A(H7N9)病毒感染危险?Health care workers often come into contact with patients with infectious diseases. Therefore, WHO recommends that appropriate infection prevention and control measures be consistently applied in health care settings, and that the health status of health care workers be closely monitored. Together with standard precautions, health care workers caring for those suspected or confirmed to have influenza A(H7N9) infection should use additional precautions (http://www.who.int/csr/resources/publications/swineflu/WHO_CDS_EPR_2007_6/en/index.html).卫生保健工作者经常接触传染病患者。因此,WHO建议在卫生保健机构中，适当的感染预防和控制措施应一贯使用,卫生保健工作者的健康状况被密切监控。连同标准预防措施，照顾那些疑似或确诊甲流A(H7N9)病毒感染患者的卫生保健工作者应使用额外的预防措施(http://www.who.int/csr/resources/publications/swineflu/WHO_CDS_EPR_2007_6/en/index.html)。14. What investigations have begun?14. 已经开始的调查有那些?Local and national health authorities are taking the following measures, among others: ? Enhanced surveillance for pneumonia cases of unknown origin to ensure early detection and laboratory confirmation of new cases; ? Epidemiological investigation, including assessment of suspected cases and contacts of known cases;? Close collaboration with animal health authorities to determine the source of the infection.当地和国家卫生当局正在采取以下措施,其中:?增强监测未知原因引起的肺炎病例，以确保早期检测和实验室确认新病例;?流行病学调查,包括疑似病例的评估和确诊病例的接触;?与动物卫生当局密切合作以确定感染源。15. Does this influenza virus pose a pandemic threat?15.该流感病毒会造成大流行的威胁吗?Any animal influenza virus that develops the ability to infect people is a theoretical risk to cause a pandemic. However, whether the influenza A(H7N9) virus could actually cause a pandemic is unknown. Other animal influenza viruses that have been found to occasionally infect people have not gone on to cause a pandemic.任何有感染人能力的动物流感病毒都有理论上导致流感大流行的风险。然而,甲流A(H7N9)病毒是否可以导致流感大流行是未知的。其他曾发现的可偶尔感染人的动物流感病毒没有导致流感的大流行。16. Is it safe to travel to China?16.去中国旅行安全吗?The number of cases identified in China is very low. WHO does not advise the application of any travel measures with respect to visitors to China nor to persons leaving China.已确定的病例数量在中国是非常低的。WHO对去中国的游客或离开中国的人群不提供任何旅行措施建议。17. Are Chinese products safe?17.中国产品是安全的吗?There is no evidence to link the current cases with any Chinese products. WHO advises against any restrictions to trade at this time.没有证据显示当前情况与任何中国产品有联系。WHO建议，反对此时对中国产品的任何限制贸易。